Annoying Hum from Amplifier
Recently had the Alps pot and a service done on my Audio Analogue Puccini SE (non remote version). When checking out the amp before bringing it home, I listened to in an audition room hooked up to a pair of Harbeth monitors and all seemed great.
On getting home, I basically just swapped it over with the emergency backup amp I was using (an even older Rotel RA-903AX), which to be fair had been doing a great job up til that point.
Right from powering on, I noticed a buzzing hum coming from both speakers that got louder when the volume was turned up.
I then went about a series of tests to see what might be causing the issue:-
- Tried all of the inputs - hum still there!
- Tied unplugging all devices except loudspeakers and power - still there!
- Swapped mains cable and socket - still there!
- Tried different set of speakers - still there!
Apart from the annoying hum, the amp sounds great, it's just noticeably distracting even when quiet music is playing.
Scratching my head on this one as I don't think it's a ground loop or earthing issue and the other amp works fine?
Going to test it again tonight but wondered if anyone on here has any ideas before I take it back to the guys who serviced it (who, I have to say, seem very competent and helpful)?
A mainly digital setup with a musical amplifier and endearing 1970's speakers. A CD player that hardly ever gets used and a turntable that is good enough to remind my how enjoyable my old vinyl is. Some cables and things.